const generics triage
I went through all const generics issues and closed all issues which are already fixed.
Some issues already have a regression test but were not closed. Also doing this as part of this PR.
uff r? @eddyb @varkor
closes#61936closes#62878closes#63695closes#67144closes#68596closes#69816closes#70217closes#70507closes#70586closes#71348closes#71805closes#73120closes#73508closes#73730closes#74255
Fix typo in std::mem::transmute documentation
`u32::from_ge_bytes` function does not exist; replace with `u32::from_be_bytes`.
It is clear that `u32::from_le_bytes` is not meant from the context; the latter is used correctly while `from_be_bytes` is misspelled.
Fix 44056 test with debug on macos.
The test `codegen/issue-44056-macos-tls-align.rs` fails on macos if `debug-assertions` is enabled in `config.toml`. It has the following error:
```
/Users/eric/Proj/rust/rust/src/test/codegen/issue-44056-macos-tls-align.rs:9:11: error: CHECK: expected string not found in input
// CHECK: @STATIC_VAR_1 = thread_local local_unnamed_addr global <{ [32 x i8] }> zeroinitializer, section "__DATA,__thread_bss", align 4
^
/Users/eric/Proj/rust/rust/build/x86_64-apple-darwin/test/codegen/issue-44056-macos-tls-align/issue-44056-macos-tls-align.ll:1:1: note: scanning from here
; ModuleID = 'issue_44056_macos_tls_align.3a1fbbbh-cgu.0'
^
/Users/eric/Proj/rust/rust/build/x86_64-apple-darwin/test/codegen/issue-44056-macos-tls-align/issue-44056-macos-tls-align.ll:9:1: note: possible intended match here
@STATIC_VAR_1 = thread_local global <{ [32 x i8] }> zeroinitializer, section "__DATA,__thread_bss", align 4
^
```
Comparing the output, the actual output is missing the text "`local_unnamed_addr`".
The fix here is to ignore `local_unnamed_addr`, as it doesn't seem relevant to the test.
Remove some `ignore-stage1` annotations.
These tests appear to no longer need the `ignore-stage1` marker.
- `run-make-fulldeps/issue-37839` and `run-make-fulldeps/issue-37893`: I believe these were due to the use of proc-macros, and probably were just missed in #49219 which fixed the proc-macro compatibility.
- `compile-fail/asm-src-loc-codegen-units.rs`: This was due to an old issue with landing pads (as mentioned in the linked issue #20184). `-Zno-landing-pads` was an option when building the first stage (it was much faster), but somewhere along the way (I think the switch from makefiles to rustbuild), the option was removed.
- NOTE: This test doesn't actually test what it was originally written for, and is probably mostly pointless now. This test was asserting the message "build without -C codegen-units for more exact errors", but that was removed in #42682. It is now in essence identical to `asm-src-loc.rs`.
Ignoring test case: [codegen] repr-transparent-aggregates-1.rs for aarch64
Ignoring test case: [codegen] repr-transparent-aggregates-1.rs for aarch64.
Copyright (c) 2020, Arm Limited.
rustdoc: glue tokens before highlighting
Fixes#72684.
This commit also modifies the signature of `Classifier::new` to avoid
copying the source being highlighted.
Don't pollute docs/suggestions with libstd deps
Currently dependency crates of the standard library can sometimes leak
into error messages such as when traits to import are suggested.
Additionally they can leak into documentation such as in the list of
"all traits implemented by `u32`". The dependencies of the standard
library, however, are intended to be private.
The dependencies of the standard library can't actually be stabl-y
imported nor is the documentation that relevant since you can't import
them on stable either. This commit updates both the compiler and rustdoc
to ignore unstable traits in these two scenarios.
Specifically the suggestion for traits to import ignore unstable traits,
and similarly the list of traits implemented by a type excludes unstable
traits.
This commit is extracted from #73441 where the addition of some new
dependencies to the standard library was showed to leak into various
error messages and documentation. The intention here is to go ahead and
land these changes ahead of that since it will likely take some time to
land.
Don't run `everybody_loops` for rustdoc; instead ignore resolution errors
r? @eddyb
cc @petrochenkov, @GuillaumeGomez, @Manishearth, @ecstatic-morse, @marmeladema
~~Blocked on https://github.com/rust-lang/rust/pull/73743~~ Merged.
~~Blocked on crater run.~~ Crater popped up some ICEs ([now fixed](https://github.com/rust-lang/rust/pull/73566#issuecomment-656934851)). See [crater run](https://crater-reports.s3.amazonaws.com/pr-73566/index.html), [ICEs](https://github.com/rust-lang/rust/pull/73566#issuecomment-653619212).
~~Blocked on #74070 so that we don't make typeck_tables_of public when it shouldn't be.~~ Merged.
Closes#71820, closes#71104, closes#65863.
## What is the motivation for this change?
As seen from a lengthy trail of PRs and issues (https://github.com/rust-lang/rust/pull/73532, https://github.com/rust-lang/rust/pull/73103, https://github.com/rust-lang/rust/issues/71820, https://github.com/rust-lang/rust/issues/71104), `everybody_loops` is causing bugs in rustdoc. The main issue is that it does not preserve the validity of the `DefId` tree, meaning that operations on DefIds may unexpectedly fail when called later. This is blocking intra-doc links (see https://github.com/rust-lang/rust/pull/73101).
This PR starts by removing `everybody_loops`, fixing #71104 and #71820. However, that brings back the bugs seen originally in https://github.com/rust-lang/rust/pull/43348: Since libstd documents items for all platforms, the function bodies sometimes do not type check. Here are the errors from documenting `libstd` with `everybody_loops` disabled and no other changes:
```rust
error[E0433]: failed to resolve: could not find `handle` in `sys`
--> src/libstd/sys/windows/ext/process.rs:13:27
|
13 | let handle = sys::handle::Handle::new(handle as *mut _);
| ^^^^^^ could not find `handle` in `sys`
error[E0425]: cannot find function `symlink_inner` in module `sys::fs`
--> src/libstd/sys/windows/ext/fs.rs:544:14
|
544 | sys::fs::symlink_inner(src.as_ref(), dst.as_ref(), false)
| ^^^^^^^^^^^^^ not found in `sys::fs`
error[E0425]: cannot find function `symlink_inner` in module `sys::fs`
--> src/libstd/sys/windows/ext/fs.rs:564:14
|
564 | sys::fs::symlink_inner(src.as_ref(), dst.as_ref(), true)
| ^^^^^^^^^^^^^ not found in `sys::fs`
```
## Why does this need changes to `rustc_resolve`?
Normally, this could be avoided by simply not calling the `typeck_item_bodies` pass. However, the errors above happen before type checking, in name resolution itself. Since name resolution is intermingled with macro expansion, and rustdoc needs expansion to happen before it knows all items to be documented, there needs to be someway to ignore _resolution_ errors in function bodies.
An alternative solution suggested by @petrochenkov was to not run `everybody_loops` on anything containing a nested `DefId`. This would solve some of the immediate issues, but isn't bullet-proof: the following functions still could not be documented if the items in the body failed to resolve:
- Functions containing a nested `DefId` (https://github.com/rust-lang/rust/issues/71104)
- ~~Functions returning `impl Trait` (https://github.com/rust-lang/rust/pull/43878)~~ These ended up not resolving anyway with this PR.
- ~~`const fn`, because `loop {}` in `const fn` is unstable (https://github.com/rust-lang/rust/issues/43636)~~ `const_loop` was just stabilized.
This also isn't exactly what rustdoc wants, which is to avoid looking at function bodies in the first place.
## What changes were made?
The hack implemented in this PR is to add an option to ignore all resolution errors in function bodies. This is enabled only for rustdoc. Since resolution errors are ignored, the MIR generated will be invalid, as can be seen in the following ICE:
```rust
error: internal compiler error: broken MIR in DefId(0:11 ~ doc_cfg[8787]::uses_target_feature[0]) ("return type"): bad type [type error]
--> /home/joshua/src/rust/src/test/rustdoc/doc-cfg.rs:51:1
|
51 | / pub unsafe fn uses_target_feature() {
52 | | content::should::be::irrelevant();
53 | | }
| |_^
```
Fortunately, rustdoc does not need to access MIR in order to generate documentation. Therefore this also removes the call to `analyze()` in `rustdoc::run_core`. This has the side effect of not generating all lints by default. Most lints are safe to ignore (does rustdoc really need to run liveness analysis?) but `missing_docs` in particular is disabled when it should not be. Re-running `missing_docs` specifically does not help, because it causes the typechecking pass to be run, bringing back the errors from #24658:
```
error[E0599]: no method named `into_handle` found for struct `sys::unix::pipe::AnonPipe` in the current scope
--> src/libstd/sys/windows/ext/process.rs:71:27
|
71 | self.into_inner().into_handle().into_raw() as *mut _
| ^^^^^^^^^^^ method not found in `sys::unix::pipe::AnonPipe`
|
```
Because of #73743, we only run typeck on demand. So this only causes an issue for functions returning `impl Trait`, which were already special cased by `ReplaceFunctionWithBody`. However, it now considers `async fn f() -> T` to be considered `impl Future<Output = T>`, where before it was considered to have a concrete `T` type.
## How will this affect future changes to rustdoc?
- Any new changes to rustdoc will not be able to perform type checking without bringing back resolution errors in function bodies.
+ As a corollary, any new lints cannot require or perform type checking. In some cases this may require refactoring other parts of the compiler to perform type-checking only on-demand, see for example #73743.
+ As a corollary, rustdoc can never again call `tcx.analysis()` unless this PR is reverted altogether.
## Current status
- ~~I am not yet sure how to bring back `missing_docs` without running typeck. @eddyb suggested allowing lints to opt-out of type-checking, which would probably be another rabbit hole.~~ The opt-out was implemented in https://github.com/rust-lang/rust/pull/73743. However, of the rustc lints, now _only_ missing_docs is run and no other lints: https://github.com/rust-lang/rust/pull/73566#issuecomment-650213058. We need a team decision on whether that's an acceptable tradeoff. Note that all rustdoc lints are still run (`intra_doc_link_resolution_failure`, etc). **UPDATE**: This was deemed acceptable in https://github.com/rust-lang/rust/pull/73566#issuecomment-655750237
- ~~The implementation of optional errors in `rustc_resolve` is very brute force, it should probably be moved from `LateResolver` to `Resolver` to avoid duplicating the logic in many places.~~ I'm mostly happy with it now.
- This no longer allows errors in `async fn f() -> T`. This caused breakage in 50 crates out of a full crater run, all of which (that I looked at) didn't compile when run with rustc directly. In other words, it used to be that they could not be compiled but could still be documented; now they can't be documented either. This needs a decision from the rustdoc team on whether this is acceptable breakage. **UPDATE**: This was deemed acceptable in https://github.com/rust-lang/rust/pull/73566#issuecomment-655750237
- ~~This makes `fn typeck_tables_of` in `rustc_typeck` public. This is not desired behavior, but needs the changes from https://github.com/rust-lang/rust/pull/74070 in order to be fixed.~~ Reverted.
Constify most non-trait `Duration` methods as described in #72440
The remaining methods could probably be made const once https://github.com/rust-lang/rust/pull/72449 lands with support for `f<32|64>::is_finite()`.
Reduce the amount of interning and `layout_of` calls in const eval.
r? @ghost
If we just want to get at some bits of a constant, we don't need to intern it before extracting those bits.
Also, if we want to read a `usize` or `bool`, we can fetch the size without invoking a query.
